Filter for a Smoking Article

ABSTRACT

The invention provides a filter element for a smoking article. The filter element comprises a plug of filter material, a tobacco core extending substantially longitudinally through the plug of filter material, and wrapping means wrapped around at least a portion of a longitudinally extending surface of the tobacco core. The filter element can be used in a variety of smoking articles.

The present invention relates to filters for smoking articles.

It is well known that filtration of smoke in a smoking article, such asa cigarette may affect the taste and flavour characteristics of aproduct when smoked. Filters commonly include adsorbent materials, suchas activated carbon, to reduce certain components of the smoke duringsmoking. However, activated carbon in a filter can adversely affect thetaste and/or flavour characteristics of a cigarette.

Therefore, in a first aspect of the invention, there is provided afilter element for a smoking article, the filter element comprising aplug of filter material, a tobacco core extending substantiallylongitudinally through the plug of filter material, and wrapping meanswrapped around at least a portion of a longitudinally extending surfaceof the tobacco core.

The inventors have found that the provision of the substantiallylongitudinal tobacco core improves the flavour of smoke (which comprisesgas and particulate matter) that is inhaled by a smoker. Furthermore,the provision of the wrapping means ensures that the tobacco remainswithin the core within the plug of filter material, and that the smokeis directed therealong.

Preferably, the tobacco core extends substantially longitudinallybetween mutually opposing end faces of the plug of filter material.Preferably, the tobacco core extends in a direction which issubstantially parallel to a side face of the plug of filter material,which side face is preferably substantially perpendicular to one or bothend faces. Preferably, the tobacco core extends through an inner portionof, and is surrounded by, the filter material. Preferably, the tobaccocore extends through substantially the centre of the plug of filtermaterial.

Advantageously, the tobacco core is disposed in close proximity with thepath of the gaseous flow as it moves through the filter element, and istherefore able to affect various characteristics of the gaseous flowbefore the flow reaches the smoker's mouth. Furthermore, because thetobacco core is disposed substantially longitudinally within the plug offilter material, it does not adversely affect the direction or rate ofgaseous flow, and so the smoker does not detect a significant differencein the resistance to draw therethrough.

The tobacco core may comprise shredded tobacco, powdered tobacco,reconstituted tobacco, tobacco stem, tobacco fibres, tobacco sheetand/or cut tobacco. However, preferably the tobacco core comprises cuttobacco lamina, cut tobacco blend and/or tobacco stem.

The tobacco core may form a tobacco rod of any cross-section. Forexample, the tobacco core may form a tobacco rod of triangular or squarecross-section. However, preferably the tobacco core forms a tobacco rodof circular cross-section. Hence, the tobacco core may be substantiallycylindrical in shape.

The wrapping means may be substantially permeable to air, such thatsmoke may pass therethrough in to the tobacco core as a smoker inhales.The wrapping means may be formed of any conventional paper material. Forexample, the wrapping means may comprise plugwrap or paper, for examplecigarette paper. The wrapping means may be perforated. The wrappingmeans may be a reconstituted wrapper, or a tobacco sheet wrapper. Thewrapping means may comprise tobacco leaf. The wrapping means may beimpervious.

The wrapping means may be in contact with substantially all of thelongitudinally extending side surface of the tobacco core. Preferably,the wrapping means circumscribes the tobacco. However, the wrappingmeans may not be disposed around at least one end face, and preferablyeach end face, of the tobacco core.

The tobacco core may comprise, or be derived from, at least alongitudinal section of a tobacco rod of a smoking article, such as acigarette, cigar or cigarillo, or the like, i.e. the smokeable sectionof the smoking article. It will be appreciated that the longitudinalsection of the tobacco rod will comprise a wrapper, such as cigarettepaper or the like, and that this wrapper forms the wrapping means of thefilter element of the first aspect.

It is preferred that the diameter of the longitudinal section of thetobacco rod is less than the diameter of the plug of filter material,and hence filter element according to the first aspect, such that itforms the tobacco core extending therethrough. Standard-sized cigarettestend to have a diameter of about 7.5 mm to about 9.5 mm (preferably 8-12mm), whereas slim-sized cigarettes tend to have a diameter of about 2-6mm. Therefore, because the diameter of the tobacco rod of a slim-sizedcigarette is less than that of a standard-sized cigarette, the inventorsenvisage using a longitudinal extending section of the tobacco rod of aslim-sized smoking article to form the wrapped tobacco core of a filterelement for use in filter of a standard-sized smoking article. Theinventors believe that they are the first to consider using the tobaccorod section of a slim-sized smoking article to form a tobacco core inthe filter of a standard-sized smoking article.

Hence, in a second aspect of the invention, there is provided a filterelement for a smoking article, the filter element comprising a plug offilter material, and a tobacco core extending substantiallylongitudinally through the plug of filter material, wherein the tobaccocore comprises, or is derived from, a longitudinal section of a tobaccorod of a smoking article.

The tobacco core may comprise, or be derived from, a longitudinalsection of a tobacco rod of a slim-sized smoking article. By using alongitudinal section of a wrapped tobacco rod of a slim-sized smokingarticle, the manufacture of standard-sized filter elements may befacilitated. Furthermore, advantageously, it is easier to change thetobacco in the longitudinal core extending through the filter material,thereby providing different tobacco styles and tastes in a range offilter elements.

It will be appreciated that there are many different types of slim-sizedsmoking articles from which the tobacco core may be derived, and thatthe dimensions of such slim-sized smoking articles varies from brand tobrand. However, the tobacco core in the filter element of the first orsecond aspect may be between 3 mm and 8 mm in diameter, preferablybetween 3 mm and 7 mm in diameter, more preferably between 3.5 mm and6.5 mm in diameter, and most preferably between 4 mm and 6 mm indiameter.

Once prepared, the tobacco core may be encased by filter material toform the filter element of the first or second aspect. The plug offilter material may comprise any suitable filter media, which will beknown to the skilled technician. A preferred filter material comprisescellulose acetate. The diameter of the plug of filter material may bebetween 5 mm and 15 mm, preferably between 6 mm and 12 mm, morepreferably between 7 mm and 10 mm, and most preferably between 7 mm and9 mm.

Preferably, the ratio of the diameter of the plug of filter material tothe diameter of the tobacco core is between 0.5:1 and 10:1, morepreferably between 1:1 and 5:1, even more preferably between 1:1 and3:1, and most preferably between 1.5:1 and 2:1.

The filter element of the first or second aspect may comprise aflavourant. In embodiments where a flavourant is used, the flavourantmay be incorporated in the plug of filter material. However, preferablythe flavourant is incorporated in the tobacco core. For example,flavourant may be sprayed onto the tobacco material prior to formationinto a rod.

It will be appreciated that the filter element according to the first orsecond aspect may be used in the manufacture of a filter, for use in asmoking article.

Hence, according to a third aspect of the invention, there is provided afilter for a smoking article, the filter comprising a filter elementaccording to the first or second aspect.

The filter of the third aspect may comprise a plurality of filterelements according to the first or second aspect, in which a tobaccocore extends through a plug of filter material.

For example, the filter may comprise 2, 3, 4, 5 or more filter elementsof the first or second aspect, in which adjacent filter elements mayeither be connected to each other, or which elements may be separatedfrom each other by other filter elements (which may not be in accordancewith the first or second aspect).

Hence, the filter may comprise a plurality of filter elements, at leastone of which is a filter element according to the first or second aspectof the invention. For example, it is envisaged that, in one embodiment,in addition to comprising one or more filter elements according to thefirst or second aspect (ie. containing the tobacco core), the filter ofthe third aspect may also comprise an adsorbent filter element, whichelement comprises an adsorbent material. The adsorbent filter element isprovided to adsorb and, hence, reduce certain components of the smokeduring smoking. The adsorbent filter element may comprise a plug offilter material in which the adsorbent material is dispersed. The filtermaterial may be cellulose acetate. A preferred adsorbent material isactivated carbon. The activated carbon may be in the form of granularactivated carbon, which is preferably distributed substantiallythroughout the volume of the plug of filter material. Preferably, theadsorbent filter element does not include a tobacco core.

In another embodiment, in addition to comprising one or more filterelements according to the first or second aspect (ie. containing thetobacco core), the filter of the third aspect may also comprise a filterelement, which comprises filter material (such as, cellulose acetate),and which does not include a tobacco core or adsorbent material.

The filter may comprise at least two, and preferably at least threefilter elements, provided that at least one filter element is inaccordance with the first or second aspect. Preferably, the filtercomprises a filter element according to the first or second aspect, anadsorbent filter element comprising adsorbent, and a filter element,which does not include adsorbent or a tobacco core. Preferably, multiplefilter elements are arranged longitudinally of one another with the endface of one filter element abutting the end face of an adjacent filterelement. It is preferred that the filter elements have substantiallysimilar diameters. It should be appreciated that the various filterelements may be in any order in the filter, as illustrated in FIGS. 3and 4.

The filter element of the first or second aspect, or the filter of thethird aspect, may be incorporated into a smoking article.

Hence, according to a fourth aspect of the invention, there is provideda smoking article comprising a filter element according to the first orsecond aspect, or a filter according to the third aspect.

The smoking article preferably comprises a section or rod of smokeablematerial, such as tobacco. As used herein, the term “smoking article”includes smokeable products such as cigarettes, cigars and cigarilloswhether based on tobacco, tobacco derivatives, expanded tobacco,reconstituted tobacco or tobacco substitutes and also heat-not-burnproducts.

The section of smokeable material and the filter may be attached bytipping paper.

According to a fifth aspect of the invention, there is provided a methodof manufacturing a filter element for a smoking article, the methodcomprising providing a tobacco core through a plug of filter material,wherein the tobacco core extends substantially longitudinally throughthe plug of filter material, and wherein wrapping means is wrappedaround at least a portion of a longitudinally extending surface of thetobacco core.

According to a sixth aspect, there is provided a method of manufacturinga filter element for a smoking article, the method comprising providinga tobacco core through a plug of filter material, wherein the tobaccocore extends substantially longitudinally through the plug of filtermaterial, and wherein the tobacco core comprises, or is derived from, alongitudinal section of a tobacco rod of a smoking article.

The method of the sixth aspect may comprise a step of arranging alongitudinal section of a tobacco rod of a slim-sized smoking article,such that it extends substantially longitudinally through the plug offilter material. Preferably, the method of the sixth aspect comprisescutting the slim-sized tobacco rod into a section of suitable lengthprior to being arranged in the plug of filter material.

The methods of the fifth or sixth aspect preferably comprise a step ofintroducing the tobacco core into substantially the centre of the filtermaterial. The methods may comprise using guide means to guide thetobacco core as a tow of filter material is formed therearound. Theguide means may comprise a guide tube through which the tobacco core isentrained. As the core exits the guide means, it is preferablysurrounded by filter material.

All of the features described herein (including any accompanying claims,abstract and drawings), and/or all of the steps of any method or processso disclosed, may be combined with any of the above aspects in anycombination, except combinations where at least some of such featuresand/or steps are mutually exclusive.

For a better understanding of the invention, and to show how embodimentsof the same may be carried into effect, reference will now be made, byway of example, to the accompanying Figures, in which:

FIG. 1 shows a perspective view of a smoking article, including a rod ofsmokeable material, a filter in accordance with the invention, andtipping paper attaching the rod and filter together;

FIG. 2 shows a cross-sectional side view of a first embodiment of thefilter according to the invention;

FIG. 3 shows a cross-sectional side view of a second embodiment of thefilter; and

FIG. 4 shows a cross-sectional side view of a third embodiment of thefilter.

Referring to FIG. 1, there is shown a smoking article 2, in the form ofa cigarette, which includes a filter 4 in accordance with the invention.Even though the Figures show the smoking article 2 as a cigarette, itshould be appreciated that the smoking article 2 may take other forms,such as cigars and cigarillos etc, which may also include the filter 4according to the invention.

Referring to FIG. 1, the smoking article 2 comprises a generallycylindrical paper-wrapped rod 6 of smokeable material, such as tobacco,which is co-axially attached to the filter 4 by tipping paper 8, whichis glued around one end of the rod 6 and the filter 4.

Referring to FIG. 2, there is shown a first embodiment of the filter 4attached to the rod of tobacco 6. In this embodiment, the filter 4 ismade up of a single, filter element 12 about 27 mm in length, whichconsists of a continuous plug of filter material 20 (for example,cellulose acetate) having a diameter of 9 mm. The filter element 12 hasfirst and second generally circular end faces 22, 24, and acircumferential or longitudinally extending side surface 26substantially perpendicular to the first and second end faces 22, 24.

As shown in FIG. 2, a cylindrical tobacco core 10 having a diameter of 3mm extends between the two end faces 22, 24 through the plug of filtermaterial 20. In order to retain the tobacco as a core 10, it is wrappedin plugwrap or cigarette paper 11. The paper 11 is substantiallypervious to air, such that smoke can pass therethrough as a smokerinhales. The tobacco core 10 is substantially parallel with thelongitudinally extending surface 26 of the filter element 12, andextends substantially through the centre of the plug of filter material20.

In some embodiments, the tobacco core 10 is derived from a tobacco rodwhich would otherwise be used in the manufacture of a superslimcigarette, examples of which are sold under the trade name Vogue(dimensions: 5 mm×99 mm) or Kent Nanotek (dimensions: 5 mm×83 mm), whichmay be obtained from British American Tobacco Company, and available inEurope and Russia. It is envisaged that the tobacco core 10 consists ofcut tobacco lamina, a cut tobacco blend or cut tobacco stems, which iswrapped in plugwrap or cigarette paper 11. Hence, the tobacco rodsection of a suitable superslim cigarette consisting of a tobacco corewrapped in cigarette paper is used to form the tobacco core 10 wrappedin plugwrap 11 of the filter element 12 of the present invention.

The wrapped tobacco core 10 is approximately 3 mm in diameter, which isthen introduced into the centre of the filter material 20. One method ofintroducing the tobacco core 10 in to the plug of filter material 20 inthe manufacture of the filter element 12 as follows. The method involvesentraining the tobacco core 10 through the lumen of a guide tube havinga diameter of about 5 mm. Simultaneously, a supply of fibrous filtermaterial 20 (e.g. cellulose acetate) is passed through a series ofblooming rollers so that it is de-crimped. A tow of de-crimped filtermaterial 20 is then formed around the core 10 as it exits the guidetube, to thereby form a continuous rod of filter material 20 enclosingthe wrapped tobacco core 10. The rod may then be cut up in to sectionsof appropriate length to produce the completed filter element 12 asshown in FIG. 2. The length of the filter element 12 will depend on thetype of filter 4 required. For example, a standard cigarette filter 4 isabout 27 mm in length. In the embodiment shown in FIG. 2, the whole 27mm length of the filter 4 consists of the filter element 12, such thatthe core 10 extends all the way along. However, FIGS. 3 and 4 illustrateother embodiments, in which the filter 4 comprises a shorter section ofthe filter element 12 containing the core 10 in combination with othersections, as described below.

Referring to FIG. 3, there is a shown a second embodiment of the filter4 attached to the rod of tobacco 6. The filter 4 comprises a pluralityof different discrete filter elements 12, 14, 16, each of which may havea different material composition. In this embodiment, the filter 4includes three different filter elements 12, 14, 16. Each filter element12, 14, 16 is generally cylindrical in shape having substantiallyequivalent diameters. Each filter element 12, 12, 16 is wrapped by alayer of thin sheet material in the form of a wrapper known as plugwrap(not shown), which may be formed of conventional paper materials. Thefilter element 16 that is farthest from the tobacco rod 6 (and whichwill be closest to the smoker's mouth when in use) comprises a generallycylindrical tow of filter material 20, such as cellulose acetate. Thefilter material 20 provides a filter through which smoke may pass as asmoker inhales on the cigarette. The filter element 12 that is disposedadjacent element 16 contains a continuous plug of filter material 20having the tobacco core 10 extending substantially longitudinallytherethrough. This filter element 12 is similar to that shown in FIG. 1,except that it does not extend along the entire length of the filter 4.

The third filter element 14 that is disposed between the filter element12 containing the tobacco core 10 and the tobacco rod 6 comprises a plugof filter material 20, in which an adsorbent, such as activated carbon18, has been dispersed. The activated carbon 18 may be in the form ofgranular activated carbon 18, which is distributed evenly throughout thevolume of the plug of cellulose acetate 20 in a “Dalmatian” style, as isknown in the art, and as shown in FIG. 3. Alternatively, the activatedcarbon 18 may be sprinkled onto a sticky exterior surface 26 of the plugof cellulose acetate 20, or adhered to the inner surface of the plugwrapsurrounding the cellulose acetate, or may be adhered to a cotton threadsurrounded by the plug of cellulose acetate 20 (not shown). Theactivated carbon 18 could also be held in a cavity surrounded by theplug of cellulose acetate 20. The activated carbon 18 is provided toimprove the characteristics of the smoke that is inhaled by removingtoxic chemicals.

Referring to FIG. 4, there is shown a third embodiment of the filter 4attached to the tobacco rod 6. In this embodiment, the filter 4 includesthe same three filter elements 12, 14, 16 as in the second embodiment,as described above, except that the order of the elements has beenchanged. As shown in FIG. 4, the filter element 16 that is farthest fromthe tobacco rod 6 comprises filter material 20, such as celluloseacetate, as in the second embodiment. However, in the third embodiment,the filter element 12 that is disposed adjacent element 16 contains aplug of filter material 20, in which particles of activated carbon 18have been dispersed. Finally, the third filter element 12 disposedbetween element 14 and the rod of tobacco 6 contains a continuous plugof filter material 20 through which the tobacco core 10 extends.Accordingly, the positions of filter elements 12, 14 have been swappedin the second and third embodiments.

As shown in FIGS. 3 and 4, the filter elements 12, 14, 16 are arrangedlongitudinally of one another with the end face 22, 24 of each filterelement 12, 14, 16 abutting the next. Although the three filter elements12, 14, 16 are shown in FIGS. 3 and 4 as being substantially equal inlength, it will be appreciated that they could have different lengths.For example, in FIGS. 3 and 4, the filter element 12 containing thetobacco core 10 could be 12 mm in length, and the other elements 14, 16could be 7.5 mm each, such that the total length of the filter 4 is 27mm. In addition, it will be appreciated that the filter 4 may compriseonly the two filter elements. For example, the filter 4 may comprise thefilter element 12 containing the tobacco core 10 (about 15 mm long) andthe filter element 16 containing only filter material 20 (about 12 mmlong), in either order. Alternatively, the filter 4 may comprise thefilter element 12 containing the tobacco core 10 and the filter element14 containing activated carbon 18, in either order.

Also, the filter 4 may comprise more than three filter elements 12, 14,16. For example, the filter 4 may comprise first and second filterelements 16 composed of cellulose acetate, a third filter element 14comprising cellulose acetate and activated carbon 18, and a fourthfilter element 12 comprising the longitudinal tobacco core 10, asdescribed above. It will be appreciated that the various filter elements12, 14, 16 may be arranged in the filter 4 in a variety of alternativeorders. However, in each embodiment, at least one filter element 12containing the tobacco core 10 is included in the filter 4.

Referring to FIG. 1 once again, the filter 4 is located at a mouth-endof the smoking article 2 such that a gaseous flow, comprising smokedrawn from the rod 6 of smokeable material, moves through the filter 4before entering the mouth of a smoker. The tobacco core 10 is located inone or more filter elements 12, and extends longitudinally between theend faces 22, 24 of a plug of filter material 20, as described inrelation to FIG. 2. In this way, the tobacco core 10 is disposed inclose proximity with the path of the gaseous flow as it moves throughthe filter 4, and is therefore able to affect various characteristics ofthe gaseous flow before the flow reaches the smoker's mouth.

The tobacco core 10 may, for example, affect the overall properties ofthe gaseous flow such that the taste and flavour of the gaseous flow areimproved. One application of the tobacco core 10 is to replace a degreeof the taste and flavour characteristics of the gaseous flow which maybe lost as the gaseous flow moves through the filter material 20, or theactivated carbon 18, which is known to affect the taste and flavour oftobacco smoke. The inventors have surprisingly found that thearrangement of the tobacco core 10 extending longitudinally through theplug of filter material 20 improves the flavour of the smoke withoutcompromising the flow characteristics of the smoke. The invention alsoincludes further modifications and variations falling within the scopeof the claims.

1. A filter element for a smoking article, the filter element comprisinga plug of filter material, a tobacco core extending substantiallylongitudinally through the plug of filter material, and wrapping meanswrapped around at least a portion of a longitudinally extending surfaceof the tobacco core.
 2. The filter element according to claim 1, whereinthe tobacco core extends substantially longitudinally between mutuallyopposing end faces of the plug of filter material.
 3. The filter elementaccording to claim 2, wherein the tobacco core extends in a directionwhich is substantially parallel to a side face of the plug of filtermaterial, which side face is substantially perpendicular to one or bothend faces.
 4. The filter element according to claim 1, wherein thetobacco core extends through an inner portion of, and is surrounded by,the filter material.
 5. The filter element according to claim 1, whereinthe tobacco core extends through substantially the center of the plug offilter material.
 6. The filter element according to claim 1, wherein thetobacco core comprises shredded tobacco, powdered tobacco, reconstitutedtobacco, tobacco fibers, tobacco sheet, cut tobacco lamina, cut tobaccoblend or tobacco stem.
 7. The filter element according to claim 1,wherein the tobacco core is substantially cylindrical in shape.
 8. Thefilter element according to claim 1, wherein the wrapping means issubstantially permeable to air.
 9. The filter element according to claim1, wherein the wrapping means is formed of any conventional papermaterial.
 10. The filter element according to claim 1, wherein thewrapping means is in contact with substantially all of thelongitudinally extending side surface of the tobacco core.
 11. Thefilter element according to claim 1, wherein the tobacco core comprises,or is derived from, at least a longitudinal section of a tobacco rod ofthe smoking article.
 12. A filter element for a smoking article, thefilter element comprising a plug of filter material, and a tobacco coreextending substantially longitudinally through the plug of filtermaterial, wherein the tobacco core comprises, or is derived from, alongitudinal section of a tobacco rod of the smoking article.
 13. Thefilter element according to claim 12, wherein the tobacco corecomprises, or is derived from, the longitudinal section of the tobaccorod of a slim-sized smoking article.
 14. The filter element according toclaim 12, wherein the tobacco core in the filter element is between 3 mmand 8 mm in diameter.
 15. The filter element according to claim 12,wherein the filter material comprises cellulose acetate.
 16. The filterelement according to claim 12, wherein the diameter of the plug offilter material is between 5 and 15 mm.
 17. A filter for the smokingarticle, the filter comprising the filter element according to claim 12.18. The filter according to claim 17, wherein the filter comprises aplurality of filter elements, at least one of which is a filter elementcomprising a plug of filter material, a tobacco core extendingsubstantially longitudinally through the plug of filter material, andwrapping means wrapped around at least a portion of a longitudinallyextending surface of the tobacco core.
 19. The filter according to claim17, wherein the filter comprises an adsorbent filter element, whichelement comprises an adsorbent material.
 20. The filter according toclaim 19, wherein the adsorbent material is activated carbon.
 21. Thefilter according to claim 17, wherein the filter comprises the filterelement, which comprises filter material, and which does not include thetobacco core or adsorbent material.
 22. A smoking article comprising afilter according to claim
 17. 23. A method of manufacturing a filterelement for a smoking article, the method comprising providing a tobaccocore through a plug of filter material, wherein the tobacco core extendssubstantially longitudinally through the plug of filter material, andwherein wrapping means is wrapped around at least a portion of alongitudinally extending surface of the tobacco core.
 24. A method ofmanufacturing a filter element for a smoking article, the methodcomprising providing a tobacco core through a plug of filter material,wherein the tobacco core extends substantially longitudinally throughthe plug of filter material, and wherein the tobacco core comprises, oris derived from, a longitudinal section of a tobacco rod of a smokingarticle.
 25. The method according to claim 24, wherein the methodcomprises arranging the longitudinal section of the tobacco rod of aslim-sized smoking article, such that it extends substantiallylongitudinally through the plug of filter material.
 26. The methodaccording to claim 23, wherein the method comprises introducing thetobacco core into substantially the center of the filter material. 27.The filter element according to claim 1, wherein the tobacco core in thefilter element is between 3 mm and 8 mm in diameter.
 28. The filterelement according to claim 1, wherein the tobacco core in the filterelement is between 4 mm and 6 mm in diameter.
 29. The filter elementaccording to claim 1, wherein the filter material comprises celluloseacetate.
 30. The filter element according to claim 1, wherein thediameter of the plug of filter material is between 5 mm and 15 mm. 31.The filter element according to claim 1, wherein the diameter of theplug of filter material is between 7 mm and 9 mm.
 32. A filter for thesmoking article, the filter comprising the filter element according toclaim
 1. 33. A smoking article comprising a filter element according toclaim
 1. 34. The filter element according to claim 12, wherein thetobacco core in the filter element is between 4 mm and 6 mm in diameter.35. The filter element according to claim 12, wherein the diameter ofthe plug of filter material is between 7 mm and 9 mm.
 36. The filteraccording to claim 17, wherein the filter comprises a plurality offilter elements, at least one of which is a filter element comprising aplug of filter material, and a tobacco core extending substantiallylongitudinally through the plug of filter material, wherein the tobaccocore comprises, or is derived from, a longitudinal section of a tobaccorod of the smoking article.
 37. The method according to claim 24,wherein the method comprises introducing the tobacco core intosubstantially the center of the filter material.